1. Field of the Invention
The present invention relates to a thermal power generation plant remote operation system and, in particular, relates to a remote control system for starting and stopping a plurality of such plants and fee collection processing applied to such system.
2. Conventional Art
Starting and stopping operation of a thermal power plant associates with a variety of concerned installations which relate each other, and includes temperature rising and lowering operations of machines and apparatuses having large thermal capacities, because such thermal power generation unit fundamentally combusts fuel, convents the thermal energy into mechanical energy and finally into electrical energy. In connection with the starting operation, as shown in FIG. 5, for every single thermal power generation plant 100 respective control units such as a boiler control unit (function) 110, a turbine control unit (function) 120 and an auxiliary sequence control unit (function) 130 connected to a power generation plant network 150 are operated from an operator monitoring operation unit 140, and a starting operation is initiated by performing backward counting from a target paralleling (rated load reaching) timing. Then, an operator successively operates individual units and starts the plant while monitoring and confirming the plant condition according to a starting operation sequence. With regard to the starting, it takes even in a most rapid instance about one hour after initiating starting preparation and actually performing parallel making in the line until building up to a target output, and depending on the standstill condition it takes a few hours, during this starting period, it is required to perform monitoring and confirming of the conditions of processes and machines over items in the number of from several tens to several hundreds as well as after correctly judging these information to open and close values and to start and stop pumps and fans in the number of several tens to several hundreds. The operation of stopping is substantially the same as the starting operation as explained above.
The starting and stopping operation can be achieved only after correctly judging the plant condition and performing a proper operation as has been explained above, however, depending on a manner of operation the time required for the starting and stopping operation may be prolonged, and contrary because of rapid starting and stopping the life time of the machines such as a turbine and a boiler sometime results in to be shortened as has been planned. The requirement from a power transmission system side is to keep paralleling (or a target load reaching) timing and decoupling (paralleling off) timing as a target timing of performing starting and stopping operation, in that it is required, when electric power demand is increasing, to properly make parallel and to increase output and to thereby perform electric power generation corresponding to the demand load, and when the electric power demand is decreasing, to perform decoupling and to decrease the output rapidly. One of the most important problems is to make paralleling at a required timing without delay after initiating a starting operation of the concerned electric power generation unit as well as to perform decoupling at the required timing after initiating a stopping operation.
When starting a unit, a boiler is warmed up and a turbine in a form of rotating body is rotated from a standstill condition to an rpm corresponding to a frequency of the concerned power transmission line, however, conditions (such as temperature and internal pressure) of the boiler and turbine in a form of solid body and associating machines and apparatuses vary depending on such as standstill period, manner of stopping operation, existence and absence and kinds of works during standstill, therefore, the manner of starting operation varies depending on the conditions above and the time required for the starting is also varies.
Steady state operation of an electric power generation plant is mostly automated by a dedicated control unit for a boiler and a turbine without necessitating intervention of an operator, however, with regard to the starting and stopping operation, since highly intelligent judgements and greatly many operations are required, such operations are performed individually either by operators at each of the concerned plant, while monitoring the plant condition or by installing such as control use computer and automating control unit which are provided with a function of causing automated starting and stopping operation and by making use of the same by operators at each of the concerned plants. Technology of the control use computer and automating control unit which are provided with a function of causing automated starting and stopping operation has already been established, therefore, it is possible to perform starting and stopping according to a predetermined sequence without needing intervention of operators or by requiring the operators a few selections.
Operation in an electric power generation plant is roughly divided into the following four stages;    (1) during a steady state loading operation,    (2) starting process,    (3) stopping process, and    (4) standstill condition.
Among these stages, since the standstill condition is one in which the plant is stopped, neither operation nor monitoring are required. During the steady state loading, since a large scale process in which fuel is combusted and the thermal energy is converted into mechanical energy and then to electrical energy, the monitoring thereof is always required. However, other than the transient condition from static to dynamic and from dynamic to static a machine operation is stable which is true for all of machine operations, therefore, number of items to be operated is a few. Accordingly, a plant monitoring during a steady state loading operation does not, in particular, require operators to attend all the time but requires to watch important parameters whether the same are stable until detecting an abnormality.
Contrary, when starting a plant, it is necessary to perform a proper operation timely after carefully checking conditions of machines and a apparatuses, auxiliary machines and processes in the plant which also depends on the condition when the plant was stopped, and such requires operators to have high technology and a correct judgement and operation. When stopping a plant, although the requirement is slightly low, it is necessary to perform correct operation with reference to a lot of information. On one hand, an intermediate load service in which starting and stopping operation is frequently repeated tends to become common in a thermal electric power generation plant, therefore, in order to perform correctly such starting and stopping operation, it is the first thing to obtain experienced operators.
However, since training of such operators requires substantial time and cost, and other than large electric power companies there are no training facilities and also these are many entrepreneurs who want to enter into electric power generation business such as industry use and IPP, but have anxieties how to practice actual operation after starting the operating. Further, even if operators are obtained, when the plant is started every day and is stopped every night, although such depends on the plant application, one cycle of starting-steady state operation-stopping requires about 16 hours, therefore, the operators are required to work in two or three shifts with one team of about 3 through 5 operators. If the plant is to be operated on Saturday and Sunday, number of teams has to be increased such as three to four teams so as to permits to take holidays by turn which requires to obtain many operators such as 9 to 20 and costs a substantial personnel expense. Even in large electric power companies owning many power generation plants, acquiring of operators is difficult and payment of personal expense cost is a large burden, therefore, they are continuously trying to reduce number of operators per unit such as by centralizing a plurality of plants and an intermediate level management of a plurality of plants.
Further, although there has been a control use computer and automating control unit which has a function of performing an automated starting and stopping operation, except for a plant which is required to perform starting and stopping operation every day, such provision of an expensive installation having the automating function is not profitable for starting and stopping operation every one week or a few times in a year. Moreover, it is not a best way in view of personnel expense to station many excellent persons as operators in an electric power generation plant for starting the plant from early morning. Although, even during a steady state operation operators are required to monitor many operating conditions, however, when the machines and apparatuses are normally operated, information to be watched is limited, therefore, such condition can be sufficiently covered by a less operators.
Accordingly, in these power generation plants it is desired that when an operation management of electric power generation plant including starting and stopping operation by a limited number of operator attendance required for steady state loading operation, the starting and stopping operation of the concerned electric power generation plant never becomes a burden of these operators.
Further, when automating the starting and stopping operation of a plant, it is required to perform a variety of adjustments depending on the characteristics of the concerned plant, however, under a circumstance where the construction period is shortened year by year and time for test run can not be shared sufficiently, it is becomes difficult to perform adjustment which reflects the plant characteristic at the time of test run completion and permits an optimum starting and stopping from any plant conditions. Further, the application (frequency of starting and stopping operations) of thermal electric power generation plants varies for every plant and further the application at the time of planning varies depending on electric power demand circumstance. For example, an electric power generation plant planned for a base application can be changed to an intermediate loading application (service). Therefore, it is necessary to perform an optimum starting and stopping operation in response to such application change flexibly for life time management of the concerned plant and for maintenance cost reduction, therefore, in order to study, plan and adjust these problems professional engineers are needed. However, it is difficult to obtain such engineers for the individual electric power generation plants, therefore, at present it is hard to say that an optimum starting and stopping operation is performed in many electric power generation plants.